Just for kicks, I thought I would catalogue the missing Admiral uniform variants seen in the series/movies, but not yet included in-game. I, for one, would love to see all of these make it into STO eventually.
This uniform was a more formal variant of the Enterprise jumpsuit, featuring a sharp necktie!
Wrath of Khan era
This is a variant of the regular TWOK uniform with gold trim on that jacket and service ribbons. There were also additional cuff straps denoting rank.
There's one Admiral's uniform from this era in STO already, but there were several others seen on screen.
The first was a fairly simple jacket with gold trim with a black belt (Type A on the Memory Alpha page).
Next, there was an interesting tunic with some interesting gold braiding around the shoulders, and coloured piping on the pants. Interesting, the rank insignia appeared vertically on the collar (Type C).
There was also a variant with a V-shaped black section on the tunic (Type D).
Finally, there was a simple jacket with gold trip (up the centreline, rather than to the side; Type E).
First Contact/Late DS9 era
This uniform is in-game, but has appeared with a plain rectangular belt buckle which is not currently an option.
Alternate future "Endgame" era
Admiral Janeway was seen in "Endgame" wearing a variant of the alternate future uniform (already in game) which featured gold trim on the jacket.